OBJECTIVES: The objective of this study was to describe the antibiotic treatment patterns among patients with newly-diagnosed Lyme disease (LD). Some published treatment guidelines specify short-course antibiotic treatment for early LD lasting 10-28 days, but there are conflicting recommendations. Little is known about real-world LD treatment patterns.  METHODS: Patients newly diagnosed with LD (ICD-9: 088.81) in 2010-2012 were identified in the Truven Health MarketScan® Commercial and Medicare Supplemental Databases